Positioning apparatus and positioning method

Abstract

The object is to provide a technology for appropriately making the centimeter positioning available in automotive applications. A positioning apparatus determines a standalone positioning solution including a vehicle position, determines a float solution including the vehicle position and a carrier phase bias, determines an integer ambiguity, determines a fix solution including the vehicle position, sets any one of the standalone positioning solution, the float solution, the fix solution, and a non-positioning solution indicating no existence of a solution as a positioning solution, and predicts a positioning error of the positioning solution as a positioning error of the vehicle position per epoch.

The invention claimed is: 
     
         1 . A positioning apparatus, comprising:
 GNSS obtaining circuitry to obtain a piece of observation data generated by a GNSS receiver including, for each of positioning signals from a plurality of GNSS satellites, a pseudo range, a carrier phase, and a Doppler shift frequency, and a piece of orbit data of the plurality of GNSS satellites;   positioning augmentation data obtaining circuitry to obtain positioning augmentation data from positioning augmentation satellites or the Internet;   positioning-based satellite selecting circuitry to select positioning-based satellites from among the plurality of GNSS satellites based on a communication quality of the GNSS satellites;   standalone positioning solution calculating circuitry to determine a standalone positioning solution, based on the pieces of observation data and a piece of orbit data of the positioning-based satellites without using the positioning augmentation data;   float solution calculating circuitry to determine a float solution including a carrier phase bias, based on the pieces of observation data and the piece of orbit data of the positioning-based satellites, and the positioning augmentation data;   search and test circuitry to determine an integer ambiguity based on the carrier phase bias of the float solution;   fix solution calculating circuitry to determine a fix solution based on the pieces of observation data and the piece of orbit data of the positioning-based satellites, the positioning augmentation data, and the integer ambiguity; and   satellite positioning error predicting circuitry to set any one of, the standalone positioning solution, the float solution, the fix solution, and an indication of no existence of a solution, as a positioning solution, and predict a positioning error of the positioning solution per epoch, wherein the epoch corresponds to a cycle of operation of the positioning apparatus,   wherein the satellite positioning error predicting circuitry:   predicts a positioning error of the float solution per epoch, based on a relationship between the positioning error of the float solution and information on at least one of a constellation of the positioning-based satellites, an elapsed time after receipt of the positioning augmentation data, observation statuses of the positioning-based satellites, or a converged status of the float solution, the relationship being obtained by learning the information and the positioning error of the float solution; and   predicts a positioning error of the fix solution per epoch, based on a relationship between the information and the positioning error of the fix solution, the relationship being obtained by learning the information and the positioning error of the fix solution, and   wherein the positioning apparatus further comprises:
 a dead reckoning circuitry to estimate a position of a vehicle using a sensor; 
 a hybrid positioning circuitry to determine a hybrid positioning solution, based on the position of the vehicle estimated by the dead reckoning circuitry, and the standalone positioning solution; and 
 a hybrid positioning error predicting circuitry to predict, when one of the float solution and the fix solution is determined, a positioning error of the hybrid positioning solution, based on a positioning error of the one of the float solution and the fix solution, and a difference between the one of the float solution and the fix solution and the hybrid positioning solution. 
   
     
     
         2 . The positioning apparatus according to  claim 1 ,
 wherein each of the positioning signals further includes an ionospheric delay error,   the positioning signals include a first positioning signal and a second positioning signal that are in different frequency bands, and   the positioning-based satellite selecting circuitry:   determines first pseudo-range residuals, based on a comparison between the pseudo ranges and the carrier phases or the Doppler shift frequencies all of which are included in the positioning signals being received;   determines second pseudo-range residuals by offsetting the ionospheric delay error of the first positioning signal against the ionospheric delay error of the second positioning signal when having both of the first positioning signal and the second positioning signal;   selects preliminary positioning-based satellites whose communication quality is higher than or equal to a first threshold from among the plurality of GNSS satellites, based on at least one of the first pseudo-range residuals or the second pseudo-range residuals of the plurality of GNSS satellites; and   selects the positioning-based satellites whose communication quality is higher than or equal to a second threshold higher than the first threshold and whose number of pieces of observation data is lower than or equal to a threshold, from among the plurality of GNSS satellites based on the at least one of the first pseudo-range residuals or the second pseudo-range residuals of the plurality of GNSS satellites, when the number of pieces of observation data of the preliminary positioning-based satellites exceeds a threshold.   
     
     
         3 . The positioning apparatus according to  claim 1 ,
 wherein the positioning apparatus learns the relationship between the information and the positioning error of the float solution and the relationship between the information and the positioning error of the fix solution.   
     
     
         4 . The positioning apparatus according to  claim 1 ,
 wherein the float solution calculating circuitry determines the float solution per epoch when a predetermined computation condition is satisfied, irrespective of whether the search and test circuitry determines the integer ambiguity, and   the search and test circuitry determines the integer ambiguity when the positioning error of the fix solution is larger than a first threshold and pseudo range residuals of the positioning-based satellites are smaller than a second threshold, until radio waves of the positioning-based satellites are interrupted or shielded since the search and test circuitry determines the integer ambiguity, or until the positioning-based satellites are updated since the search and test circuitry determines the integer ambiguity.   
     
     
         5 . The positioning apparatus according to  claim 1 ,
 wherein when one of the float solution and the fix solution is determined, the satellite positioning error predicting circuitry predicts a positioning error of the standalone positioning solution, based on a positioning error of the one of the float solution and the fix solution, and a difference between the one of the float solution and the fix solution and the standalone positioning solution.   
     
     
         6 . The positioning apparatus according to  claim 1 ,
 when none of the float solution and the fix solution is determined, the hybrid positioning circuitry corrects a positioning error of the standalone positioning solution using positioning errors of the standalone positioning solution calculated up to a predefined epoch, and determines the hybrid positioning solution based on the corrected standalone positioning solution.   
     
     
         7 . A positioning method, comprising:
 obtaining a piece of observation data that is generated by a GNSS receiver including, for each of positioning signals from a plurality of GNSS satellites, a pseudo range, a carrier phase, and a Doppler shift frequency, and a piece of orbit data of the plurality of GNSS satellites;   obtaining positioning augmentation data from positioning augmentation satellites or the Internet;   selecting positioning-based satellites from among the plurality of GNSS satellites based on a communication quality of the GNSS satellites;   determining a standalone positioning solution, based on the pieces of observation data and a piece of orbit data of the positioning-based satellites without using the positioning augmentation data;   determining a float solution including a carrier phase bias, based on the pieces of observation data and the piece of orbit data of the positioning-based satellites, and the positioning augmentation data;   determining an integer ambiguity based on the carrier phase bias of the float solution;   determining a fix solution based on the pieces of observation data and the piece of orbit data of the positioning-based satellites, the positioning augmentation data, and the integer ambiguity;   setting any one of, the standalone positioning solution, the float solution, the fix solution, and an indication of no existence of a solution, as a positioning solution, and predicting a positioning error of the positioning solution per epoch, the epoch corresponding to a cycle of operation of the positioning method;   predicting a positioning error of the float solution per epoch, based on a relationship between the positioning error of the float solution and information on at least one of a constellation of the positioning-based satellites, an elapsed time after receipt of the positioning augmentation data, observation statuses of the positioning-based satellites, or a converged status of the float solution, the relationship being obtained by learning the information and the positioning error of the float solution; and   predicting a positioning error of the fix solution per epoch, based on a relationship between the information and the positioning error of the fix solution, the relationship being obtained by learning the information and the positioning error of the fix solution,   wherein the positioning method further comprises:
 estimating a position of a vehicle using a sensor; 
 determining a hybrid positioning solution based on the estimated position of the vehicle, and the standalone positioning solution; and 
 predicting, when one of the float solution and the fix solution is determined, a positioning error of the hybrid positioning solution, based on a positioning error of the one of the float solution and the fix solution, and a difference between the one of the float solution and the fix solution and the hybrid positioning solution. 
   
     
     
         8 . A positioning apparatus, comprising:
 GNSS obtaining circuitry to obtain a piece of observation data generated by a GNSS receiver including, for each of positioning signals from a plurality of GNSS satellites, a pseudo range, a carrier phase, and a Doppler shift frequency, and a piece of orbit data of the plurality of GNSS satellites;   positioning augmentation data obtaining circuitry to obtain positioning augmentation data from positioning augmentation satellites or the Internet;   positioning-based satellite selecting circuitry to select positioning-based satellites from among the plurality of GNSS satellites based on a communication quality of the GNSS satellites;   standalone positioning solution calculating circuitry to determine a standalone positioning solution, based on the pieces of observation data and a piece of orbit data of the positioning-based satellites without using the positioning augmentation data;   float solution calculating circuitry to determine a float solution including a carrier phase bias, based on the pieces of observation data and the piece of orbit data of the positioning-based satellites, and the positioning augmentation data;   search and test circuitry to determine an integer ambiguity based on the carrier phase bias of the float solution;   fix solution calculating circuitry to determine a fix solution based on the pieces of observation data and the piece of orbit data of the positioning-based satellites, the positioning augmentation data, and the integer ambiguity;   satellite positioning error predicting circuitry to set any one of, the standalone positioning solution, the float solution, the fix solution, and an indication of no existence of a solution, as a positioning solution, and predict a positioning error of the positioning solution per epoch, wherein the epoch corresponds to a cycle of operation of the positioning apparatus;   a dead reckoning circuitry to estimate a position of a vehicle using a sensor; and   a hybrid positioning circuitry to determine a hybrid positioning solution, based on the position of the vehicle estimated by the dead reckoning circuitry, and the positioning solution,   wherein the satellite positioning error predicting circuitry:   predicts a positioning error of the float solution per epoch, based on a relationship between the positioning error of the float solution and information on at least one of a constellation of the positioning-based satellites, an elapsed time after receipt of the positioning augmentation data, observation statuses of the positioning-based satellites, or a converged status of the float solution, the relationship being obtained by learning the information and the positioning error of the float solution; and   predicts a positioning error of the fix solution per epoch, based on a relationship between the information and the positioning error of the fix solution, the relationship being obtained by learning the information and the positioning error of the fix solution,   the positioning apparatus further comprising   a controller to determine, based on the hybrid positioning solution and map data, at least one of a distance between a center of the vehicle and a center of a traveling lane through which the vehicle is traveling, a distance between the vehicle and a white line to a left of the traveling lane, or a distance between the vehicle and a white line to a right of the traveling lane, and causes a display to display a color corresponding to the at least one of the distances.   
     
     
         9 . The positioning apparatus according to  claim 8 ,
 wherein the controller determines a traveling trajectory of the vehicle and a position of each of the white lines of the traveling lane, based on the hybrid positioning solution and the map data, and causes the display to execute an alert corresponding to the traveling trajectory and the positions of the white lines.   
     
     
         10 . The positioning apparatus according to  claim 8 ,
 wherein the controller causes the display to display a position relationship between boundary lines of the traveling lane, the white lines, and the vehicle, based on the hybrid positioning solution and the map data.   
     
     
         11 . The positioning apparatus according to  claim 8 ,
 wherein the controller causes the display to guide an emergency parking zone ahead of the vehicle, based on the hybrid positioning solution and the map data.   
     
     
         12 . The positioning apparatus according to  claim 8 ,
 wherein the controller causes the display to display regional destinations for respective lanes including the traveling lane, based on the hybrid positioning solution and the map data.   
     
     
         13 . The positioning apparatus according to  claim 8 ,
 wherein the controller causes the display to execute an alert when the vehicle enters or has entered a lane through which the vehicle cannot pass, based on the hybrid positioning solution and the map data.   
     
     
         14 . The positioning apparatus according to  claim 8 , further comprising
 measurement circuitry to sense the white lines to the right and the left of the traveling lane of the vehicle, and estimate whether the traveling lane is a leftmost lane, a rightmost lane, or an inner lane, based on combinations of types of the sensed white lines,   wherein the controller causes the display to guide a lane through which the vehicle should travel, based on the hybrid positioning solution and a result of the estimation of the measurement circuitry.   
     
     
         15 . The positioning apparatus according to  claim 14 ,
 wherein the measurement circuitry senses a bump and a pothole on a road ahead of the vehicle, and an obstacle ahead of the vehicle, and   the controller causes the display to execute an alert, based on a sensing result on the obstacle.   
     
     
         16 . The positioning apparatus according to  claim 14 ,
 wherein the measurement circuitry senses an obstacle ahead of the vehicle, and   the controller causes the display to display a map per lane to which the obstacle has been mapped, based on the map data and a sensing result on the obstacle.   
     
     
         17 . The positioning apparatus according to  claim 14 ,
 wherein the measurement circuitry senses an obstacle on one side of the vehicle, using a plurality of sensing devices, and   the controller predicts a behavior of the obstacle, based on a sensing result on the obstacle.   
     
     
         18 . The positioning apparatus according to  claim 14 ,
 wherein the measurement circuitry determines a road surface condition of a road through which the vehicle is traveling, and   the controller causes the display to execute an alert, based on a determining result on the road surface condition.   
     
     
         19 . The positioning apparatus according to  claim 14 ,
 wherein the controller controls a distance between the vehicle and each of the white lines, based on the hybrid positioning solution and a sensing result on the white lines.   
     
     
         20 . The positioning apparatus according to  claim 14 ,
 wherein the controller controls a change in the traveling lane of the vehicle, based on the hybrid positioning solution, a sensing result on the white lines, and the types of the sensed white lines.   
     
     
         21 . The positioning apparatus according to  claim 14 ,
 wherein the measurement circuitry senses a vehicle parking ahead of the vehicle, and   wherein the controller allows the vehicle to overtake the parking vehicle, based on the hybrid positioning solution and a sensing result on the parking vehicle.   
     
     
         22 . The positioning apparatus according to  claim 14 ,
 wherein the measurement circuitry senses an area in front of an intersection ahead of the vehicle, and   the controller allows the vehicle to enter the area when determining that the area has a space that the vehicle can enter, based on a sensing result of the measurement circuitry.